Trouble with Pharmacy Calculations

[Pharmop]

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Most of the materials that I'm learning are pretty straight forward, however I think I'm overlooking this problem and I cannot seem to solve it. Can someone help me on how to get it started? The 70% along with the 59.14 ml seem to be throwing me off.

Rx
Salicyclic Acid 5%
Isopropy alcohol (70% v/v) ad 59.14 ml
M. Ft.

How many grams of Isopropyl alcohol are required to fill the prescription?

 

[pharmalt82]

Most of the materials that I'm learning are pretty straight forward, however I think I'm overlooking this problem and I cannot seem to solve it. Can someone help me on how to get it started? The 70% along with the 59.14 ml seem to be throwing me off.

Rx
Salicyclic Acid 5%
Isopropy alcohol (70% v/v) ad 59.14 ml
M. Ft.

How many grams of Isopropyl alcohol are required to fill the prescription?

Salicyclic Acid 5% is w/v. 5g/100ml -> 2.96g/59.14mL
Salicyclic Acid density is 1.44 g/mL, therefore: 2.06mL Salicyclic Acid will be needed.
59.14mL-2.06mL = 57.08mL of Isopropyl Alcohol 70%.
70% of 57.08mL is 39.96mL of Pure Isopropyl Alcohol.
Pure Isopropyl Alcohol Density is 0.786g/mL.
Therefore, 31.4g of Isopropyl Alcohol needed.
This assumes that the salicylic acid dissolves and causes an exact (its powder volume) increase in the volume of the solution.
This question is obviously unrealistic and BS.

 

[PharmerInPNW]

This question is obviously unrealistic and BS.

I love your conclusion haha.